"He seemed a little nervous," Lopez said. "I just whispered, I said, 'The song is so beautiful. When they hear the first few notes, they're going to start applauding. So don't worry. Just deliver the song.'"

Cooper took the stage on Sunday at Los Angeles' Dolby Theatre to sing the hit track with "A Star Is Born" co-star Lady Gaga. Afterward, Lopez, who presented the award for best production design with Chris Evans, shared her thoughts on the Academy Awards.

"He seemed a little nervous," Lopez said of Cooper during an Instagram Live video with boyfriend Alex Rodriguez. "I just whispered, I said, 'The song is so beautiful. When they hear the first few notes, they're going to start applauding. So don't worry. Just deliver the song.'"

The 49-year-old entertainer also gushed over the "Shallow" rendition after Rodriguez said that he thought the two stars were "amazing."

"Amazingly beautiful, intimate performance," Lopez said in agreement. "To have a front row seat to that was so special."

Lady Gaga and Bradley Cooper performed at the 2019 Oscars. Chris Pizzello/Invision/AP

Lady Gaga and Cooper, who play love interests Ally and Jackson in "A Star Is Born," were praised by viewers for their emotional Oscars performance. The two stars began by walking to the stage from their seats in the audience, then belted out the words and sat together on a bench as Gaga played the piano.

The moving performance even earned Gaga and Cooper a second standing ovation when they returned to their seats after a commercial break.

At the 91st Oscars, "A Star Is Born" was nominated for eight Oscars, including best picture, leading actor, and leading actress. The film took home the award for best song written for a motion picture for "Shallow."